.. _animation-simple_3danim:

animation example code: simple_3danim.py
========================================

[`source code <simple_3danim.py>`_]

::

    """
    A simple example of an animated plot... In 3D!
    """
    import numpy as np
    import matplotlib.pyplot as plt
    import mpl_toolkits.mplot3d.axes3d as p3
    import matplotlib.animation as animation
    
    def Gen_RandLine(length, dims=2) :
        """
        Create a line using a random walk algorithm
    
        length is the number of points for the line.
        dims is the number of dimensions the line has.
        """
        lineData = np.empty((dims, length))
        lineData[:, 0] = np.random.rand(dims)
        for index in range(1, length) :
            # scaling the random numbers by 0.1 so
            # movement is small compared to position.
            # subtraction by 0.5 is to change the range to [-0.5, 0.5]
            # to allow a line to move backwards.
            step = ((np.random.rand(dims) - 0.5) * 0.1)
            lineData[:, index] = lineData[:, index-1] + step
    
        return lineData
    
    def update_lines(num, dataLines, lines) :
        for line, data in zip(lines, dataLines) :
            # NOTE: there is no .set_data() for 3 dim data...
            line.set_data(data[0:2, :num])
            line.set_3d_properties(data[2,:num])
        return lines
    
    # Attaching 3D axis to the figure
    fig = plt.figure()
    ax = p3.Axes3D(fig)
    
    # Fifty lines of random 3-D lines
    data = [Gen_RandLine(25, 3) for index in range(50)]
    
    # Creating fifty line objects.
    # NOTE: Can't pass empty arrays into 3d version of plot()
    lines = [ax.plot(dat[0, 0:1], dat[1, 0:1], dat[2, 0:1])[0] for dat in data]
    
    # Setting the axes properties
    ax.set_xlim3d([0.0, 1.0])
    ax.set_xlabel('X')
    
    ax.set_ylim3d([0.0, 1.0])
    ax.set_ylabel('Y')
    
    ax.set_zlim3d([0.0, 1.0])
    ax.set_zlabel('Z')
    
    ax.set_title('3D Test')
    
    # Creating the Animation object
    line_ani = animation.FuncAnimation(fig, update_lines, 25, fargs=(data, lines),
                                  interval=50, blit=False)
    
    plt.show()
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)